Utility Rate Regulation (Regulatory Matters) (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended					9 Months Ended	12 Months Ended	1 Months Ended					9 Months Ended		12 Months Ended	9 Months Ended		1 Months Ended								9 Months Ended		1 Months Ended
	Sep. 30, 2014 Y Integer	Sep. 30, 2013	Dec. 31, 2013	Sep. 30, 2014 Pennsylvania 2013 Storms [Member]	Sep. 30, 2014 PPL Electric [Member] Pennsylvania 2013 Storms [Member]	Sep. 30, 2014 PPL Electric [Member] Hurricane Sandy [Member]	Dec. 31, 2013 PPL Electric [Member] Hurricane Sandy [Member]	Nov. 30, 2014 LGE [Member] Subsequent Event [Member] Kentucky Public Service Commission [Member]	Nov. 30, 2014 LGE [Member] Subsequent Event [Member] Kentucky Public Service Commission [Member] Electric Rates [Member]	Nov. 30, 2014 LGE [Member] Subsequent Event [Member] Kentucky Public Service Commission [Member] Gas Rates [Member]	Nov. 30, 2014 KU [Member] Subsequent Event [Member] Kentucky Public Service Commission [Member]	Nov. 30, 2014 KU [Member] Subsequent Event [Member] Kentucky Public Service Commission [Member] Electric Rates [Member]	Sep. 30, 2014 PPL Electric Utilities Corp [Member] Y Integer	Sep. 30, 2014 PPL Electric Utilities Corp [Member] Hurricane Sandy [Member]	Dec. 31, 2013 PPL Electric Utilities Corp [Member] Hurricane Sandy [Member]	Sep. 30, 2014 LG And E And KU Energy LLC [Member] Integer	Sep. 30, 2014 LG And E And KU Energy LLC [Member] Federal Energy Regulatory Commission [Member]	Nov. 30, 2014 LG And E And KU Energy LLC [Member] LGE [Member] Subsequent Event [Member] Kentucky Public Service Commission [Member]	Nov. 30, 2014 LG And E And KU Energy LLC [Member] LGE [Member] Subsequent Event [Member] Kentucky Public Service Commission [Member] Electric Rates [Member]	Nov. 30, 2014 LG And E And KU Energy LLC [Member] LGE [Member] Subsequent Event [Member] Kentucky Public Service Commission [Member] Gas Rates [Member]	Nov. 30, 2014 LG And E And KU Energy LLC [Member] KU [Member] Subsequent Event [Member] Kentucky Public Service Commission [Member]	Nov. 30, 2014 LG And E And KU Energy LLC [Member] KU [Member] Subsequent Event [Member] Kentucky Public Service Commission [Member] Electric Rates [Member]	Nov. 30, 2014 Louisville Gas And Electric Co [Member] Subsequent Event [Member] Kentucky Public Service Commission [Member]	Nov. 30, 2014 Louisville Gas And Electric Co [Member] Subsequent Event [Member] Kentucky Public Service Commission [Member] Electric Rates [Member]	Nov. 30, 2014 Louisville Gas And Electric Co [Member] Subsequent Event [Member] Kentucky Public Service Commission [Member] Gas Rates [Member]	Sep. 30, 2014 Kentucky Utilities Co [Member] Integer	Sep. 30, 2014 Kentucky Utilities Co [Member] Federal Energy Regulatory Commission [Member]	Nov. 30, 2014 Kentucky Utilities Co [Member] Subsequent Event [Member] Kentucky Public Service Commission [Member]	Nov. 30, 2014 Kentucky Utilities Co [Member] Subsequent Event [Member] Kentucky Public Service Commission [Member] Electric Rates [Member]
Regulatory Matters - United Kingdom Activities - Ofgem Review of Line Loss Calculation (Numeric) [Abstract]
Charge to income during period for line loss incentive/penalty liability	$ 65	$ 45
Liability at period end regarding line loss incentive/penalty	105		74
Regulatory Matters - Pennsylvania Activities - Storm Damage Expense Rider (Numeric) [Abstract]
Amount of regulatory liability reversed				12	12
Number of years costs will be recovered						3								3
Regulatory Matters - Pennsylvania Activities - Act 129 (Numeric) [Abstract]
Minimum term of long term supply contract under Act 129 (in years)	4												4
Maximum term of long term supply contract under Act 129 (in years)	20												20
Maximum percentage of long-term contracts that can be included in the mix of PLR supply contracts under Act 129	25.00%												25.00%
Regulatory Matters - Pennsylvania Activities - Smart Meter Rider (Numeric) [Abstract]
Maximum number of years the cost of smart meters can be depreciated	15												15
Projected cost of proposed smart meter replacement project	450												450
Regulatory Matters - Pennsylvania Activities - Distribution System Improvement Charge (Numeric) [Abstract]
Number of ratemaking mechanisms authorized for PUC approval	2												2
Minimum term for Long Term Infrastructure Improvement Plan (in years)	5												5
Maximum term for Long Term Infrastructure Improvement Plan (in years)	10												10
Number of issues assigned to the Office of Administrative Law Judge	4												4
Regulatory Matters - Federal Matters - Federal Energy Regulatory Commission Formula Rates (Numeric) [Abstract]
Number of municipal customers impacted for Federal Energy Regulatory Commission formula rate request																12										12
Approved return on equity																	10.00%										10.00%
Number of municipalities that submitted termination notices, effective 2019																9										9
Number of municipalities that submitted termination notices, effective 2017																1										1
Number of municipalities that agreed to settlement terms of rate change request																2										2
Requested return on equity for certain wholesale customers																	10.70%										10.70%
Regulatory Matters - Storm Costs (Numeric) [Abstract]
Amount of regulatory asset established						29	29							29	29
Regulatory Matters - Rate Case Proceeding / Federal Energy Regulatory Commission Formula Rates (Numeric) [Abstract]
Dollar amount requested increase in base rates with anticipated rate case filing									$ 30	$ 14		$ 153							$ 30	$ 14		$ 153		$ 30	$ 14				$ 153
Percentage requested increase in base rates with anticipated rate case filing									2.70%	4.20%		9.60%							2.70%	4.20%		9.60%		2.70%	4.20%				9.60%
Return on equity requested with anticipated rate case filing								10.50%			10.50%							10.50%			10.50%		10.50%					10.50%